COVID-19: Combination of Covid-19 vaccine & mild infection is good: S’pore expert

Singapore — An infectious disease expert explained that a combination of a Covid-19 vaccine and a mild infection of the virus was good because it activates the needed cells to fight the infection and strengthen one’s line of defence.

“What is happening now is exactly what is needed to become more resilient in safeguarding against new variants,” said Professor Ooi Eng Eong from the Duke-NUS Medical School in a Straits Times panel discussing Singapore’s road to an endemic.

Prof Ooi explained that getting vaccinated and having a mild Covid-19 infection offers better protection against current and future mutations or variants compared to only getting vaccinated or infected with the virus.

The combination of the inactivated virus in a vaccine and the live virus from infection provides a stronger line of defence, he highlighted.

Prof Ooi added that a live virus activates the body’s second line of defence called killer T cells.

The first is antibodies which prevent a virus from entering our cells. Should it fail, the killer T cells kick in to destroy the invading virus.

While mRNA vaccines such as Pfizer-BioNTech and Moderna create both antibodies and killer T cells, the latter only follows the blueprint of the original virus and can’t respond efficiently to mutations.

Prof Ooi noted that it might be the cause for lower vaccine protection against the highly transmissible Delta variant.

However, he added that a mild infection triggers the necessary killer T cells to address the invasion. It can also detect mutations along the way.

Getting infected alone does not give the same level of protection as a combination of vaccine and infection, said Prof Ooi, noting that it was already happening in Singapore and could help the population.

“That the Delta variant is now spreading in Singapore, but not to the level that results in a large number of severe cases, will serve to produce more robust immunity in our population. I think we should stay the course and not go back to heightened alert or even circuit breaker,” he said.

According to the Ministry of Health’s Covid-19 update on Tuesday (Sept 21), 82 per cent of the population has completed their vaccination process while 84 per cent has received at least one dose.

Meanwhile, MOH detected a total of 1,178 new cases of Covid-19 infection, with 1,038 in the community, 135 in the migrant worker dormitories and five imported cases.

There are 1,109 cases currently warded in hospital, with 147 cases of serious illness requiring oxygen supplementation and 17 in critical condition in the intensive care unit.

Three individuals, a female Singaporean, 62; a male Singaporean, 74; and another male Singaporean, 83, passed away due to Covid-19 complications.

In total, 65 have passed away in Singapore due to Covid-19 infection. /TISG

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